local triangle_adjust = {}

function triangle_adjust.max(x, y, z)
    local m1, m2, m3
    if x > y then
        m1 = x
        m2 = y
    else
        m1 = y
        m2 = x
    end
    if z > m1 then
        return z, m1, m2
    elseif z < m2 then
        return m1, m2, z
    else
        return m1, z, m2
    end
end

function triangle_adjust.adjust(x, y, z)
    if x >= y + z then
        print("non-triangle")
    elseif x == y and y == z then
        print("equilateral triangle")
    elseif x == y or y == z or x == z then
        print("isoceles triangle")
    else
        print("triangle")
    end
end

local a = io.read("*n")
local b = io.read("*n")
local c = io.read("*n")
if a <= 0 or b <= 0 or c <= 0 then
    print("error")
    return
end
a, b, c = triangle_adjust.max(a, b, c)
triangle_adjust.adjust(a, b, c)
